Lee (1997) carried out a photometric survey of light curve
modulation among RR Lyrae stars. The goal was to
determine the prevalence of the Blazhko effect and to
investigate the various forms the effect takes. Of the
107 stars in the sample, V442 Her (period = 0.44 days)
stood out for its extreme changes in light curve shape
and amplitude over relatively long intervals of time. We
have observed this star further and now have data from
four observing seasons. The amplitude of the V light curve
ranges from 0.29 mag to 1.40 mag. At large amplitude the
light curve is a typical of a Bailey type ab RR Lyrae star
while at small amplitude it does not resemble any type of
RR Lyrae star. The best estimate of the period of the light
curve modulation with the existing data is 885 days.
Although this is not definitive given the temporal coverage
now available, a shorter period appears unlikely from an
examination of the data. We conclude that the modulation
period of V442 Her is much longer than any other known
RR Lyrae star. If the modulation of the light curve of this
star is an example of the Blazhko effect, it represents a
very extreme case. Whether this is so or whether the
modulation is another phenomenon, this star deserves
further study.